Low-cost photographic fluid spreading apparatus

ABSTRACT

Fluid spreading apparatus for use in a camera of the selfdeveloping type having a first sheet-contacting facing surface of relatively large radius arcuate crosssectional configuration and a second substantially flat sheet-contacting facing surface which co-act to exert a compressive force on superposed sheet materials as such materials are progressively drawn therebetween. A platform extends in front of the flat sheet-contacting facing surface and is canted at a predetermined angle with respect thereto. Extending in front of this platform is a ramp which is canted at a predetermined angle with respect to the platform to guide at least some of the sheet materials onto the platform as they are advanced from a film pack towards the sheet-contacting surfaces. Edge control members connected to the arcuate sheetcontacting surface urge longitudinal edges of one of the sheets into engagement with the other sheet in advance of the sheetcontacting surfaces.

Powers et al.

[ Aug. 13, 1974 LOW-COST PHOTOGRAPHIC FLUID SPREADING APPARATUS [75] Inventors: Sheldon D. Powers, Stoneham; Earl R. Thoenen, Newburyport, both of Mass.

[73] Assignee: Polaroid Corporation, Cambridge,

Mass.

[22] Filed: Aug. 9, 1973 [21] Appl. N0.: 386,956

Related US. Application Data [63] Continuation-in-part of Ser. No. 133,906, April 14,

1971, abandoned.

Primary ExaminerSamuel S. Matthews Assistant Examiner-Alan Mathews Attorney, Agent, or FirmAlfred E. Corrigan 5 7 ABSTRACT Fluid spreading apparatus for use in a camera of the self-developing type having a first sheet-contacting facing surface of relatively large radius arcuate crosssectional configuration and a second substantially flat sheet-contacting facing surface which co-act to exert a compressive force on superposed sheet materials as such materials are progressively drawn therebetween. A platform extends in front of the flat sheetcontacting facing surface and is canted at a predetermined angle with respect thereto. Extending in front of this platform is a ramp which is canted at a predetermined angle with respect to the platform to guide at least some of the sheet materials onto the platform as they are advanced from a film pack towards the sheetcontacting surfaces. Edge control members connected to the arcuate sheet-contacting surface urge longitudinal edges of one of the sheets into engagement with the other sheet in advance of the sheet-contacting surfaces.

19 Claims, 15 Drawing Figures PATENTEDAUG 1 31914 SHEET 2 BF 3 Fig. 3b.

PATENTEU mm 3 I974 sum 3 or 3 LOW-COST PHOTOGRAPHIC FLUID SPREADING APPARATUS RELATED APPLICATION This application is in part a continuation of our copending application Ser. No. 133,906, filed April 14, 1971, now abandoned.

BACKGROUND OF THE. lNVENTlON 1. Field of the Invention This invention relates to photography and, more particularly, to improved apparatus for distributing processing fluid in a layer between a pair of superposed sheet materials.

2. Description of the Prior Art Cameras of the self-developing type generally employ a pair of spreader elements which facilitate the formation of a visible image in a photographic sheet by a diffusion-transfer process. In a typical arrangement,

, 'a sheet of photosensitive material is first exposed to image-carrying light rays to form a latent image therein.

elements themselves may typically comprise either a pair of rollers, one roller and a rigid non-rolling member, or a pair of rigid non-rolling members.

The fluid spreading process is a critical consideration in producing highquality photographic prints by a'diffusion transfer process. Much effort was required to develop, engineer and manufacture the film units and spreader elements employed in the self-developing cameras currently being marketed. The quality of the finished print provided by these photographic systems is directly related to the nature of the fluid coating applied to the photographic sheets. As is well known, suchcameras are capable of producing photographic prints generally most pleasing to the public. However, it is of the utmost importance that the sheet-contacting facing surfaces of the spreader elements be accurately formed to close tolerances.

In order to reach the mass amateur camera market, it is necessary that the cost of self-developing cameras be kept to an absolute minimum. More specifically. a major goal in the self-developing camera art is the development ofa camera which can be marketed at substantially the same price as a conventional-type camera of the same quality. This is not a simple task when one realizes that such cameras must perform all of the functions of the more conventional-type cameras, and additionally include a film processing capability.

Along these lines, experience has shown that the fluid spreadingapparatus necessarily incorporated in selfdeveloping cameras represents a significant cost element. Until recently, in commercially available systems, this apparatus traditionally comprised a pair of precision machined stainless steel rollers and a mounting arrangement'therefor which facilitated thier proper operation and frequent cleaning. In order to provide a lower-cost fluid spreading apparatus for its Big Swinger and Color Pack" cameras which are produced for the very moderately priced amateur market, the Polaroid Corporation of Cambridge, Mass. developed the spreader system described in detail in U.S. Pat. Nos. 3,485,155; 3,499,373; 3,498,196 and 3,537,371 This apparatus comprises a pair of relatively inexpensive non-rolling fluid spreader members formed of sheet metal parts. As is well known, millions of these Big Swinger and Color Pack cameras have already been sold utilizing this particular low-cost fluid spread ing system. It is self-evident that photographs produced employing such apparatus have, proven quite satisfactory. However, the ultimate goal still exists, i.e., the development of a fluid spreading system of absolute minimum cost which does not compromise the quality of the photograph furnished to the user.

Advantageously, today most self-developing camera systems utilize film magazines or packs each of which initially contains a plurality of film units. In such arrangements, different film units in each magazine are withdrawn therefrom at varying positions as they are advanced towards the fluid spreading system. It is highly desirable that this situation be accommodated bythe fluid spreading system to assure that the fluid layers associated with the various film units are substantially uniform in thickness.

Still further, the nature of the fluid layer as it is pro gressively spread between the photographic sheets affects the amount of excess fluid which must be furnished with each film unit as well as the amount and nature of the waste materials forming part of each such unit. It is therefore most desirable to provide fluid spreading systems which reduce the amount of such excess fluid and waste materials by tending to optimize the nature of the meniscus of this moving fluid layer.

An object of this invention, therefore, is to provide improved photographic apparatus for spreading a processing fluid as a layer between sheets of material.

An important object of this invention is to provide an extremely low-cost fluid spreading apparatus.

Another primary object of this invention is to provide apparatus of the type indicated which effects a uniform distribution of processing fluid with respect to. each film unit contained in a multi-film unit magazine.

A further object of this invention is to provide apparatus of the type indicated which effects an improved distribution of fluid within a body. thereof as a layer of the fluid isspread progressively across photographic sheet materials.

An additional object of this invention is to provide apparatus of the type indicated which may be produced in low-tolerance manufacturing operations.

Still another object of this invention is to provide apfrom a camera as a single unit.

SUMMARY OF THE INVENTION In its illustrated embodiment, the fluid spreading apparatus of this invention has been depicted as being employed to effect the distribution of a processing fluid in a layer between respective photographic sheets of a plurality of film units initially retained within a multiunit film pack of a conventional type. The fluid spreading apparatus itself is an integral assembly which may be inserted into and removed from the camera as a single unit. With both the fluid spreading apparatus and the film pack mounted in the camera, individual film units may be withdrawn from the film pack through the fluid spreading apparatus outwardly of the camera. However, as is conventional, the various film units are disposed at different locations within the film pack at the time they are withdrawn therefrom and therefore initially approach the fluid spreading apparatus from varying positions.

The apparatus of this invention comprises a pair of spreader elements presenting elongated juxtaposed sheet-contacting facing surfaces disposed to exert a compressive force on the pair of photographic sheets comprising each film unit as they progressively pass therebetween. One of such sheet-contacting facing surfaces is substantially flat, while the other has an arcuate cross-sectional configuration. This arrangement of a flat sheet-contacting facing surface in combination with an arcuate sheet-contacting facing surface has the advantage, when compared for instance with a pair of arcuate sheet-contacting facing surfaces, of tending to flatten" the shape of the fluid meniscus as it advances across and between the photographic sheet materials during the film processing operation.

Extending from the flat sheet-contacting facing surface in a direction towards the film pack and away from the arcuate sheet-contacting facing surface is a platform toward which each pair of photographic sheets is urged in advance of the facing surfaces by edge control members extending from the latter facing surface. Additionally, a ramp extends from this platform into the film pack and under the leading edges of the film units retained therein.

In this arrangement, the configurations of the facing surfaces permit the spreader elements on which they are formed to be produced in low-tolerance, and therefore relatively inexpensive, manufacturing operations. The angle which the platform makes with respect to the flat sheet-contacting surface controls the thickness of the fluid layer spread between the superposed sheet materials as they pass between the sheet-contacting facing surfaces. Further, this angle is selected such that, regardless of which particular film unit is being withdrawn from the camera at a given time, the imagereceiving photographic sheet is not distorted, as it approaches the platform so as to adversely affect the alignment of its corresponding image-recording photographic sheet. This situation assures fluid spreads of uniform thickness in all film units of the film pack. Still further, this angular orientation of the platform with respect to'the flat sheet-contacting facing surface is selected so as not to adversely affect the disposition of the weakened seal of the fluid containing pod, or to cause that pod to contact certain conventional elements of the camera structure, as it distends in the course of its introduction between the sheet-contacting facing surfaces of the spreading apparatus. Either of the above-mentioned conditions, if not precluded, would have adverse results on the fluid spreading operation. The ramp serves to guide various ones of the image-receiving sheets housed within the film pack as they are advanced therefrom towards the platform and sheet-contacting facingsurfaces during film processing operations.

BRIEF DESCRIPTION OF THE DRAWINGS The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of the preferred embodiment when read in connection with the accompanying drawings wherein like members have been employed in the different figures to denote the same parts and wherein:

FIG. 1 is a diagrammatic perspective view of a self- FIG. 3b is a view similar to FIG. 3a illustrating the spreader elements at such time as they are disposed in their inoperative positions; 7

FIGS. 4a, 4b and 4c are fragmentary diagrammatic views in cross-section illustrating the nature of the fluid flow pattern during the processing of the first film unit from conventional film packs utilizing different forms of fluid spreading apparatus, the form of the fluid.

spreading apparatus shown in FIG. 4c comprising the present invention;

FIGS. 5a and 5b are diagrammatic perspective views illustrating the nature of the fluid flow patterns respectively obtained with the fluid spreading apparatus depicted in FIGS. 4a and 40; 1

FIGS. 6a, 6b and 6c are diagrammatic cross-sectional views of the fluid spreading apparatus of FIG. 4b during differing stages of operations associated with the processing of various film units in a conventional multiunit film pack; and

FIGS. 7a, 7b and 7c are diagrammatic cross-sectional views of the fluid spreading apparatus of FIG. 40 during differing stages of operations associated with the processing of various film -units in a conventional multiunit film pack.

DESCRIPTION OF A PREFERRED EMBODIMENT In its illustrated embodiment, the present invention is depicted as forming part of a self-developing camera l0. As shown in FIG..l, this camera 10 is basically constituted by a main camera body 12 to which a back body member I4 is, pivotally connected. When the back body member 14 is disposed in its open position with respect to the main camera body 12, access is provided into the interior of the camera 10 for purposes of loading the camera I0 with a film pack 15 (See FIGS. 6 and 7) containing a sufficient quantity of photographic materials to produce a plurality of reflective photographic prints. These film packs may, for example, be identical to those currently marketed by the Polaroid Corporation of Cambridge, Mass, and identified as Land Pack Film Type I07 (black-and-white film) or Polacolor Land Film Type I08 (full-color film). Each of these particular film packs contains a plurality of eight ,film units. In order to produce a reflective print, each film unit includes a relatively thick, stiff sheet of image-receiving material 17; a relatively thin, flexible sheet of photosensitive image-recording material 29; a mask 19; a rupturable pod 23 of processing fluid 25; a bib 27 and a leader 21.

Forming part of the main camera body 12 is a lens and shutter housing 16 which may take a conventional form. This housing 16 is mounted at the outer end of an extensible bellows 18 provided with a suitable erecting mechanism 20. Attached at one side of the main camera body 12 is a rangefinder-viewfinder 22 that has been shown in phantom so as not to obstruct the view of certain other portions of the camera 10. A processing fluid spreading device or apparatus 24, incorporating the features of the present invention, is removably retained within the back body member 14 adjacentits free end. After the film pack has beenloaded into the camera 10, the cameras back body member 14 may be pivoted to its closed position wherein it cooperates with the main camera body 12 to form a lightsealed chamber adapted to facilitate film exposure and processing operations.

Reference is now made to FIGS. 3a, 3b, 4c and 7a-c of the drawings which more clearly depict the nature of the processing fluid spreading device 24. As shown therein, this device 24 basically comprises three components, Le, a first spreader element 26, a second spreader element 28, and an elongated rod 30, the lastmentioned component serving, in part, to pivotally connect the first two stated elements one to the other. Each of the spreader elements 26 and 28 may, for instance, advantageously be fabricated from a single sheet of metal, such as stainless steel, in relatively inexpensive metal-forming operations. By way of example,

the sheet material may have a thickness on the order of 0.025 inches.

The spreader element 28 includes a flat section 32 from which a substantially flat sheet-contacting facing surface 34 depends at approximately a 90angle. While thisfacing surface 34 is described as being substantially flat, within this context it is contemplated that it may comprise slight contours. For instance, in the preferred embodiment this substantially flat surface 34 is provided with a convex profile contour such that its center point is disposed on the order of 0.0008 inches above its ends. Extending rearwardly from this flat sheetcontacting facing surface 34, in a direction towards the film pack 15 and away from the first spreader element 26, is a platform 36. As shown in FIGS. 7a-c, a ramp 37 extends from the platform 36 into film pack 15 and under the leading edges of the film units retained therein. In this connection, the aforementioned conventional film packs 15 are provided with a cut-out 119 through which the spreading apparatus, i.e., the ramp 37, enters thereinto. This ramp 37 serves to guide at least some of the leaders 21 and image-receiving sheets 17 of film units as they are advanced from the film pack 15 towards the platform 36 and sheet-contacting facing surface 34. A support 38, provided with an upturned flange 40, is formed at the end of the ramp 37 furthermost disposed from the sheet-contacting facing surface 34. Extending upwardly from the opposite ends of the flat facing surface 34 are a pair of flanges 48 and 50 respectively provided with inwardly directed tabs 52 and 54 and outwardly depending tabs 56 and 58. When the fluid spreading device 24 is inserted into the camera l0. v

and seated against the cameras back bodymember 14, the upturned flange 40 extending from the support 38 is engaged by a clip 60 (See FIG. 1) of the came'ras back body member 14 that serves to releasably retain the device 24 in the camera. In this connection, when the camera 10 is loaded with one of the aforementioned film packs 15 and its back body member 14 is closed against the camera's main body 12, members (not shown) formed on the main camera body 12 engage the tabs 56 and 58 of the spreading device 24 to further restrict or limit movement of that device within the camera 10. Simultaneously, these tabs 56 and 58 serve to align the spreading device 24 laterally within the back body member 14.

The first spreader element 26 includes a flat section Also extending from the same side of the flat section 64 is a pin positioned midway between the ends of the spreader element 26. The lateral ends of the section 64 respectively terminate in ears 72 and 74 provided with elongated apertures 76 and 78. In order to pivotally connect the spreader elements 26 and 28 one to the other, the elongated apertures 76 and 78 of the first spreader element are first respectively-aligned with circular apertures 80 and 82 of the second spreader elements flanges 48 and 50. Then the elongated rod 30 is slid through these apertures 76, 78, 80 and 82 so that its center portion is disposed on the side of the pin 70 furthermost removed from the spreader element 28. It will thus be appreciated that the spreader element 26 may be pivoted with respect to the element 28 between operative positions as shown in FIG. 3a of the drawings and inoperative positions as shown in FIG. 3b.

When the spreader elements 26 and 28 are disposed in their inoperative positions illustrated in FIG. 3b, their sheet-contacting facing surfaces 34 and 68 are readily'accessible for inspection and/or cleaning purposes. When they are disposed in their operative positions illustrated in FIG. 3a, opposite ends of the arcuate sheet-contacting facing surface 68 are seated on spacers 92 and 94 appropriately provided on the flat sheetcontacting facing surface 34.

The section 66 of the spreader element 26 terminates in specially configured end portions 84 and 86 which respectively include wrap-around collars 88 and 90. When the spreader elements 26 and 28 are disposed in their operative positions, these collars 88 and 90 are in a close proximity to the platform 36 of spreader element 28. As the spreader elements 26 and 28 reach their operative positions, the spacers 92 and 94 establish a predetermined minimum spacing between their respective facing surfaces 34 and 68. In this connection, the rod 30 is stressed or bowed over the pin 70 and the configuration of the elongated apertures 76 and 78, in which slots the opposite ends of the rod are positioned, permits a certain amount of movement of the spreader element 26 in the direction away from the spreader element 28. Thus, at such times, the facing surfaces 34 and 68 define a pressure-generating gap 96 between the spreader elements 26 and 28, such gap having a minimum dimension as determined by the.

spacers 92 and 94. It will be recognized that this arforce on such materials under the influence of the flexible rod 30. The wrap-around collars 88 and 90 of the spreader element 26 serve to engage respective longitudinal edge portions of the photosensitive material 29 of a film unit being advanced through the pressuregenerating gap 96 in advance of the gap to move them into engagement with the longitudinal edges of the image-receiving sheet 17 to preclude escape of processing fluid from between the sheet materials 17 and 29 com prising such film unit. It should be noted at this time that although the collars press the longitudinal edge portions of the photosensitive material 29 into engagement with the corresponding edge portions of the image-receiving sheet 17, the relative stiffness of the image-receiving sheet prevents it from moving into engagement with the platform 36.

For purposes of definition, this pressure-generating gap 96 is considered as comprising a plane A (See FIG. 30) extending thereacross. When the spreader elements 26 and 28 are in their operative positions, the substantially flat sheet-contacting facing surface 34 is disposed at an angle of substantially 90 to this plane A of the pressure-generating gap 96.

When the processing fluid spreading device 24 is mounted in the camera's back body member 14 with its spreader elements 26 and 28 disposed in their operative positions, the pressure-generating gap 96 defined by the facing surfaces 34 and 68 is aligned with an elongated exit port (not shown) formed through the adjacent wall 104 (see FIG. 1) of the back body member. Also, when the back body member 14 is closed against the main camera body 12, the edge of the wall 104, in conjunction with a slotted section 106 of the main camera body 12, provides additional access into the camera 10.

As is well known, when a film pack of the type indicated is mounted in the camera and the back body member 14 thereof closed thereover, tabs (not shown) attached to the film units extend through the opening provided by the slotted section 106. By drawing on one of these tabs, after 'making an exposure, a leader attached to the associated film unit is advanced into the pressure-generating gap 96 of the fluid spreading device 24 so as to protrude through the aforementioned adjacent elongated exit port (not shown) of the camera's back body member 14. In this connection, cameras of this type are generally provided with a tab strip bar 105, (See FIGS. 6a and 7a) which serves to maintain proper alignment of the film unit as it is advanced into the pressure-generating gap 96 in the process of pulling the aforementioned tab through the opening provided by the slotted section 106. Once the leader 21 is accessible to the operator, it may be withdrawn from the camera 10 to advance the film unit, comprising the exposed image-recording sheet 29, and its associated image-receiving sheet 17 and rupturable pod 23 of processing fluid 25, through the pressure-generating gap 96 of the fluid spreading device 24. During such operation, the pod 23 is ruptured and the'processing fluid initially retained therein spread by the elements 26 and 28 in a thin layer between the photographic sheets 17 and As previously indicated, the fluid spreading device 24 of this invention has been depicted as being utilized in a camera adapted to receive certain film packs of a type presently marketed by Polaroid Corporation of Cambridge, Mass. Further, certain dimensions have been indicated on several figures of the drawings in order to impart a full understanding of the present invention. However, it is to be expressly understood that the invention is adapted for use with other types of film packs and/or film units and that the dimensions reflected on the drawings are exemplary only and therefore are not to be interpreted as restricting the scope of the disclosed invention in any manner.

As described, the fluid spreading device 24 incorporates a number of features which provide significant advantages over heretofore devised fluid spreading arrangements. A first of these important advantages may best be appreciated by referring to FIGS. 5a and 5b of the drawings. The former of these drawings diagrammatically illustrates the pattern of the fluid meniscus 107 during film processing operations employing the prior art fluid spreading device 108 depicted in FIG. 4a. That spreading device 108 comprises a pair of spreader elements 109 and 111 respectively including relatively small radius sheet-contacting facing surfaces and 112 and, as such, is similar .to the fluid spreading devices described in the aforementioned U.S. patents and that described in US. Pat. No. 3,641,908. In' contrast to FIG. 50, FIG. 5b illustrates the configuration of the fluid meniscus 114 during film processing operations employing the fluid spreading device 24 of the present invention. As stated, this latter spreading device 24 comprises the flat sheet-contacting facing surface 34 and the relatively large radius arcuate sheetcontacting facing surface 68 (See FIG. 40). It will thus be appreciated that, when compared with the prior art fluid spreading device 108, the device 24 of the present invention provides a flattened" fluid meniscus pattern during film processing operations. Importantly, as the fluid meniscus is flattened," the amount of excess fluid which must be provided for each film unit is proportionately reduced and the size of the arrangement associated with each film unit for trapping such excess fluid is similarly proportionately reduced.

By way of example, it has been determined that satisfactory pod rupturing and fluid spreading operations may be effected employing the specific fluid spreader elements 26 and 28 illustrated in FIGS. 40 and 7a-c of the drawings in conjunction with the film units of the aforementioned Polaroid Corporation film packs when the elongated rod 30 is selected to have a spring force on the order of 5 to 6 pounds. In this particular arrangement, the spreader elements 26 and 28 exert a compressive force on the film units on the order of 1 psi.

Another major advantage of the fluid spreading device 24 when compared, for instance, with the prior art device 108 is that it may be produced in lower tolerance, and therefore less expensive, manufacturing operations. In this respect, it will be appreciated that, with a given material of given thickness, both the flat surface 34 and large radius arcuate surface 68 are more easily developed than the relatively small radius arcuate sheet-contacting facing surfaces of the spreading systems described in the aforementioned patents and in US. Pat. No. 3,641,908. Additionally, the nature of the facing surfaces 34 and 68 are such as to render their alignment with respect to each other during assembly operations far less critical than the alignment which must necessarily be achieved between the prior art small radius facing surfaces 110 and 112. These considerations materially reduce the amount of scrappage experienced during high-volume manufacturing operations for producing the prior art sheet metal fluid spreading device such as that depicted in FIG. 4a.

Spreading device 24 provides a number of particularly significant advantages over a somewhat similar fluid spreading system 116 depicted in FIGS. 4/) and 6a'c and which comprises fluid spreader elements 115 and 117. Similar to the fluid spreader elements 26 and 28 of the device 24, these elements 115 and 117 respectively include a relatively large radius arcuate sheet-contacting facing surface 118 and a flat sheetcontacting facing surface 120. However, in the latter instance, a pair of wrap-around collars 122 serve to seat superposed sheet materials 17 and 29 against an extension 126 of the flat facing surface 120 that lies in the same plane with that facing surface. The fluid spreading device depicted in FIGS. 6a-c further includes a ramp 128, which extends from the end of the extension 126 to a point internally of the film pack 15.

The first of these particular advantages of the fluid spreading device 24 may best be appreciated by now referring to FIGS. 6a-c and 7ac. The film packs each initially contain eight image-receiving sheets 17 disposed in a stacked array positioned adjacent the side 132 of the film pack. In producing the first photographic print, the sheet 17 closest to the side 132 of the film pack 15 is withdrawn therefrom and progressively aligned in superposed relationship with its associated image-recording sheet 29 with a layer of processing fluid '25 being spread therebetween. The eighth, or last, photographic print produced from the materials within the film pack 15 utilizes the image-receiving sheet 17 initially disposed furthermost from the side 132 of the film pack 15.,Thus, as is well known, different ones of the image-receiving sheets 17 retained in the film pack 15 are withdrawn therefrom at differing positions. This situation is diagrammatically illustrated in FIGS. 6b and 7b, which depict the first image-receiving sheet 17 being withdrawn from respective film packs 15, and in FIGS. 60 and 7c which illustrate the eighth imagereceiving sheets 17 being withdrawn from respective film packs 15.

In FIG. 60 it will be seen that, in the case of the eighth image-receiving sheet 17, the configuration of the spreading element 117 is such as not to distort the shape of that sheet as it approaches the pressuregenerating gap 130. However, in the FIG. 6b situation, wherein the first film unit is being withdrawn from the film pack l5,the image-receiving sheet 17 is distorted by the fluid spreader element 117 as it passes from its ramp 128 onto the extension 126 causing a related distortion to occur in the associated image-recording sheet 29, i.e., the latter sheet is precluded from follow ing it otherwise natural path from the film pack 15 towards the wrap-around collars 122. This situation causes the layers of processing fluid disposed between the image-recording sheets 29 and image-receiving sheets 17 of the different film units in the film pack 15 to vary in thickness as they emerge from the pressure generating gap 130 of the fluid spreading system 116. More specifically, the differing dispositions between the sheets 17 and 29 of the first film unit and the sheets 17 and 29 of the eighth film unit as those film units approach the pressure-generating gap 'causes-the-distance between that gap and the fluid meniscus 133 to be greater in the first instance. Consequently, the shear rate of the fluid 25 in the case of the first film unit is. less than the shear rate of the fluid in the case of the,

eighth film unit thereby resulting in the aforementioned differences in the thicknesses of the fluid layers. The

undesirable consequences of such a situation are self evident.

Referring now to FIGS. 7b and 7c, which respectively illustrate the processing of the first and last film units retained within a film pack 15 employing the fluid spreading device 24 of the present invention, it will be seen that the configuration of that device is not such as to produce any distinguishable differences between the thicknesses of layers of fluid spread between the imagereceiving sheets 17 and image-recording sheets 29 of the various film units. More specifically, the platform. 36 is canted at a predetermined angle with respect to the flat sheet-contacting facing surface 34 and defines an angle with respect to the ramp 37 such that the sheet 17, whether it be that associated with the first film unit or that associated with the last film unit, is not adversely distorted as it passes from the film pack '15 to the pressure-generating gap 96. In the case of both the first and last film units, the distance between the pressure-generating gap 96 and the fluid meniscus 114 is substantially the same. This situationproduces substantially identical fluid shear rates. resulting in fluid layers of the same thickness being spread between the sheets 17 and 29 of all of the film units within the pack 15.

It has further been found that, assuming the distance which the platform 36 extends in a direction awayfrom the pressure-generating gap 96 remains unchanged, substantial uniformity exists between the thicknesses of the fluid layers produced in all eight film units retained within the film pack 15 when the angle which the platform makes with the flat facing surface 34. is on the order of 4 or greater. Importantly, in this connection, it has further been determined that by varying this angle which the platform 36 makes with the flat sheetcontacting facing surface 34, the thickness of the fluid layer spread between the sheets 17 and 29 may be varied. In other words, changing the angle which the platform makes with the substantially flat sheet-contacting surface 34, controls the thickness of the fluid layers spread by the sheetcontacting facing surfaces 34 and 68. For example, when this angle is selected at 4 the thickness of the fluid layer will be on the order of 0.0060 inches, and when this angle is selected at 6 the thickness of the fluid layer will be on the order of 0.0056 inches.

In spreading apparatus described in the aforemen: tioned US. Pat. No. 3,641,908, edge control members urge respective longitudinal edge portions of the superposed sheet materials against support surfaces in advance of a pressure-generating gap defined by a pair of relatively small radius arcuate sheet-contacting facing surfaces thereby distorting the superposed sheet materials whereas edge control members 86 and 88 merely move the longitudinal edge portions of the imagerecording material 29 into engagement with the respec tive longitudinal edge portions of the image-receiving form thickness of fluid layers spread with respect to each film unit retained within a film pack and means for controlling the thickness of the fluid layers spread v by a particular system. I It has been found desirable to have the lowermo portions of the collars 88 and 90 aligned with the edge of the arcuate facing surface 68, Le, to have those portions of the collars and the arcuate facing surface define a plane disposed parallel to the flat facing surface 34 when the elements 26 and 28 are in their operative positions. The portion of the canted platform 36 disposed adjacent those portions of the collars at such time must be spaced therefrom a carefully predetermined distance which in the preferred embodiment is on the order of 0.022 inches. The spacing thus provided is greater than the combined thicknesses of the photographic sheets 17 and 29, the mask 19 and rails (not shown) of the film units. These considerations define the location at which the canted platform intersects the substantially flat sheet-contacting facing surface 34 and, in the illustrated embodiment provides a facing surface 34 having a length of 0.060 inches.

To facilitate production operations, it is desirable that the canted platform extend in a direction away from the flat facing surface 34 at least to the end of the ears 72 and 74 which is the situation depicted in FIG. 2. By way of example, satisfactory results are then obtained when the ramp 37 depends at an angle on the order of 1 from the canted platform 36. This situation provides a canted platform having a length on the order of 0.400 inches in the illustrated embodiment.

Other important advantages of the fluid spreading device 24 of the present invention with respect to those devices depicted in FIGS. 4a and 4b can best be appreciated by now referring to FIGS. 4a, 6a and 7a. Each pod 23 of processing fluid includes a rupturable seal of the fluid from the pod through its ruptured seal 134 and between the sheets 17 and 29 will create air bubbles within the fluid 25 adversely affecting the quality of the finished print. Consequently, it is necessary to keep turbulence within the fluid 25 to an absolute mini,

mum.

The situation depicted in'FIG. 6a, and which directly results from the configuration of the fluid spreading system 116, illustrates two problems which tend to increase fluid turbulence. First, the alignment between the leader 21 and bib 27 andthe pod 23 in the vicinity of the seal 134 is distorted, when compared for instance with the situation depicted in FIG. 7a, thereby creating a relatively turbulent fluid flow condition. Also, the nature of the extension 126 of the spreader element 117 causes the distended pod 23 to be pressed against the tab strip bar 105 of the camera in a manner causing the shape of the pod to become distorted. This distortion of the distended pod 23 also tends to create a turbulent condition within the fluid 25 and it is released therefrom. in contrast to the situation in FIG. 6a, the nature of the fluid spreading device 24 with its 12 bar 105 and, further, to minimize or eliminate any misalignment between the mask 19 and bib 27 and the distended pod 23 adjacent the pods rupturabl e seal 134.

The relieved section 136 associated with the prior art fluid spreading device 108 (See FIG. 4a) immediately in advance of that device's facingsurfaces 110 and 112 serves to accommodate a portion of the distended pod as the pod is initially introduced between the facing surfaces. Thus this feature of the prior art device 108 serves in part the same function as the canted platform 36 of the fluid spreading device 24 in that it precludes misalignment of the leader 21 and bib 27 and the distended pod 23 adjacent the pods rupturable seal 134 and also precludes contact of the distended pod with the tab strip bar 105. However, in the same connection, the prior art fluid spreading device 108 has significant limitations with respect to the fluid spreading device 24. More specifically, the metal cutting and stamping operations required to provide the relieved section 136 in the device 108 represent an element of cost eliminated in the manufacturing processes associated with the production of the fluid spreading device 24. Even more importantly, such metal cutting and stamping operations can and do increase the amount of scrappage associated with the production of the fluid spreading device 108 in quantity. In this latter respect. the increased "scrappage" results from distortions periodically caused in the relatively small radius facing surface 112 during the stamping and cutting operations.

This invention may be practiced or embodied in still other ways without departing from the spirit, or essential character thereof. The preferred embodiments described herein are therefore illustrative and not restrictive, the scope of the invention being indicated by the contact between the distended pod 23 and the tabstrip appended claims and all variations which come within the meaning of the claims are intended to be-embraced therein.

What is claimed is:

1. Photographic apparatus for effecting the spreading of a processing fluid in a layer between a pair of photographic elements, comprising:

a pair of elongated juxtaposed sheet-contacting facing surfaces defining a pressure-generating gap to exert a compressive force on such photographic elements as they progressively pass therebetween in superposed relationship to effect the spreading of a layer of such fluid therebetween;

a substantially flat platform connected to and extendspaced apart edge control members positioned to engage and urge respective longitudinal edge portions of said superposed photographic elements against each other in advance of said gap. 2. The apparatus of claim 1 wherein the other sheetcontacting facing surface is arcuate in cross-section.

3. The apparatus of claim 1 wherein said platform is spaced a distance on the order of .022 inches from said edge control members.

4. The apparatusof claim 1 wherein said platform is disposed at an angle of between 84 and 86 with respect to the plane of said pressure-generating gap.

5. The apparatus of claim 1 wherein said platform is disposed at an angle of 85 with respect to the plane of said pressure-generating gap.

6. The apparatus of claim 1 wherein said apparatus comprises a pair of sheet metal spreader elements, said one sheet-contacting facing surface and said platform being formed in one of said spreader elements and said other sheet-contacting facing surface being formed in the other of said spreader elements.

7. The apparatus of claim 6 wherein said edge control members are formed in said other spreader element.

8. The apparatus of claim 1 wherein said platform is disposed at an angle of between 4 and 6 with respect to said substantially flat sheet-contacting facing surface.

9. The apparatus of claim 1 wherein said platform is disposed at an angle on the order of 5 with respect to said substantially flat sheet-contacting facing surface.

10. The apparatus of claim 1 wherein said platform is disposed at an angle of between 4 and 6 with respect to said substantially flat sheet-contacting facing surface and additionally including a ramp for supporting and guiding at least one of such photographic elements toward said canted platform as such sheet materials approach said pressure-generating gap. said ramp being canted at an acute angle with respect to said platform. v

11. The apparatusof claim 1 further including means for rapidly attaching and detaching said apparatus as a single unit from a camera.

12. Apparatus for use in a camera of the selfdeveloping type including an enclosed housing having an elongated exit port through which photographic film units, each of such film units comprising a first and a second sheet, may be withdrawn therefrom and means for mounting a plurality of such film units within such housing with said second sheets thereof disposed in a stacked array such that the leading edge of each such second sheet is spaced a given distance from the plane of such exit port and each such second sheet is disposed generally parallel to a plane perpendicular to such firstmentioned plane so that each is spaced a different distance from such second-mentioned plane, the improvement comprising:

a pair of fluid spreader elements presenting elongated juxtaposed sheet-contacting facing surfaces defining a pressure-generating gap disposed to exert a compressive force on each pair of such first and second sheets as they progressively pass there between in superposed relationship towards said exit port to effect the spreading of a layer of processing fluid between each such pair of sheets, one of said facing surfaces being substantially flat and extending perpendicular to the plane of said gap;

means for assuring that fluid layers of substantially the same thickness are spread between all suchpairs of sheets as they are withdrawn from such camera, said means comprising a platform extending from a point adjacent one of said sheetcontacting facing surfaces towards such stacked array and away from said other sheet-contacting facing surface, and means forurging progressive sections of each such pair of sheets against each other as they are advanced from such stacked array toward said pressuregenerating gap, one side of such stacked array of second sheets lying in a plane disposed on the other sideof said substantially flat sheet-contacting facing surface from said other sheet-contacting facing surface and said platform extending from an end of said substantially flat sheebcontacting facing surface to a point intermediate said substantially flat sheet-contacting facing surface and such stacked array of second sheets; and

means for supporting and guiding such second sheets as they approach said platform extending from the end of said platform furthermost removed from said substantially flat sheet-contacting facing surface to a point under such stacked arrayof second sheets.

13. The apparatus of claim 12 wherein said platform is substantially flat and disposed at an angle on the order of 5 degrees with respect to said substantially flat sheet-contacting surface and said support and guiding means comprises a substantially flat ramp disposed at an angle on the order of 1 with respect to said platform.

l4. Photographic apparatus for spreading a processing fluid as a layer between two sheets of material responsive to relative motion being effected between said apparatus and such sheets. a first of such sheets comprising. a relatively flexible photosensitive element having a latent image recorded thereon and the second of such sheets comprising a relatively stiff image-receiving sheet, said apparatus comprising: i

a first fluid spreader element formed of sheet material and including an elongated substantially flat sheet-contacting facing surface;

a second fluid spreader element formed of sheet metal and including an elongated sheet-contacting facing surface having an arcuate cross-sectional configuration; and means for pivotally connecting said spreader elements together for selective movement between an operative positionwherein said facing surfaces are disposed in juxtaposed relationship to exert a compressive force on such sheets asthey progressively pass therebetween in superposed relationship to effect the spreading of a layer of such fluid between such sheets and an inoperative position wherein said facing surfaces are readily accessible for cleaning purposes, said flat sheet-contacting facing surface being disposed adjacent such second sheet during such fluid spreading operations and said arcuate sheet-contacting facing surface being disposed adjacent such first sheet during such fluid spreoading operations.

15. Photographic apparatus for spreading a processing fluid as a layer between two sheets of material responsive to relative motion being effected between said apparatus and such sheets, comprising:

a first fluid spreader element formed of sheet metal and including an elongated substantially flat sheetcontacting facing surface;

a second fluid spreader element formed of sheet metal and including an elongated sheet-contacting facing surface having an arcuate cross-sectional configuration; and

ing means comprises means for facilitating a given amount of displacement of at least one of said elements away from the other of said elements when said elements are disposed in their said operative positions and means for yieldably urging said elements towards one another at such times.

l7. Photographic apparatus for spreading a processing fluid as a layer between two photographic sheets responsive to relative motion being effected between said apparatus and such sheets, said apparatus comprising:

a first fluid spreader element formed of sheet metal and including an elongated substantially flat sheetcontacting facing surface;

a second fluid spreader element formed of sheet metal and including an elongated sheet-contacting facing surface having an arcuate cross-sectional configuration;

means for mounting said fluid spreader elements with their said sheet-contacting facing surfaces disposed in juxtaposition to define a gap therebetween and for yieldably urging said fluid spreader elements toward each other;

a substantially flat platform connected and extending from said substantially flat sheet-contacting facing surface in the direction that such photographic sheets are intended to approach said gap, said platform being disposed at an acute angle with respect to the plane of said gap and configured to provide a surface adapted to underlie such photographic sheets as they approach said gap;

a ramp extending at an acute angle from said platform for supporting and guiding at least one of such photographic sheets toward said platform as such photographic sheets approach said gap; and means for urging spaced apart longitudinal edge portions of such photographic sheets toward each other but not into engagement with said platform.

18. The apparatus of claim 17 wherein said platform is disposed at an angle of between 4 and 6 with re- H spect to said substantially flat sheet-contacting facing surface and said ramp is disposed at an angle on the order of 1 with respect to said platform.

19. Photographic apparatus for effecting the spreading of a processing fluid in a layer between a pair of sheet materials comprising:

a pair of elongated juxtaposed sheet-contacting facing surfaces defining a pressure-generating gap to exert a compressive force on such sheets as they progressively pass therebetween in superposed relationship to effect the spreading of a layer of such fluid therebetween, one of said sheet-contacting facing surfaces being substantially flat and extending perpendicular to the plane of said gap;

means for controlling the thickness of the layer of such fluid spread between such sheets as they pass between said sheet-contacting facing surfaces, said means comprising a substantially flat platform canted at an angle of between 4 and 6 with respect to said one facing surface as it approaches said pressure-generating gap, said platform extending from a point adjacent said one sheet-contacting facing surface away therefrom in the direction towards which such sheets are advanced towards such sheet-contacting facing surfaces, and means for urging progressive sections of such superposed sheets against each other as they are advanced towards said pressure-generating gap; and

a ramp for supporting and guiding at least one of such sheet materials as such sheet materials approach said pressure-generating gap, said ramp being disposed at an angle on the order of 1 with respect to said platform. 

1. Photographic apparatus for effecting the spreading of a processing fluid in a layer between a pair of photographic elements, comprising: a pair of elongated juxtaposed sheet-contacting facing surfaces defining a pressure-generating gap to exert a compressive force on such photographic elements as they progressively pass therebetween in superposed relationship to effect the spreading of a layer of such fluid therebetween; a substantially flat platform connected to and extending from one of said sheet-contacting facing surfaces in the direction that such photographic elements are intended to approach said gap, said platform being disposed at an acute angle with respect to the plane of said gap so as to be located in nonsupporting relation with such photographic elements as they approach said gap and said one sheet-contacting facing surface is substantially flat and extends perpendicular to the plane of said pressure-generating gap; and spaced apart edge control members positioned to engage and urge respective longitudinal edge portions of said superposed photographic elements against each other in advance of said gap.
 2. The apparatus of claim 1 wherein the other sheet-contacting facing surface is arcuate in cross-section.
 3. The apparatus of claim 1 wherein said platform is spaced a distance on the order of .022 inches from said edge control members.
 4. The apparatus of claim 1 wherein said platform is disposed at an angle of between 84* and 86* with respect to the plane of said pressure-generating gap.
 5. The apparatus of claim 1 wherein said platform is disposed at an angle of 85* with respect to the plane of said pressure-generating gap.
 6. The apparatus of claim 1 wherein said apparatus comprises a pair of sheet metal spreader elements, said one sheet-contacting facing surface and said platform being formed in one of said spreader elements and said other sheet-contacting facing surface being formed in the other of said spreader elements.
 7. The apparatus of claim 6 wherein said edge control members are formed in said other spreader element.
 8. The apparatus of claim 1 wherein said platform is disposed at an angle of between 4* and 6* with respect to said substantially flat sheet-contacting facing surface.
 9. The apparatus of claim 1 wherein said platform is disposed at an angle on the order of 5* with respect to said substantially flat sheet-contacting facing surface.
 10. The apparatus of claim 1 wherein said platform is disposed at an angle of between 4* and 6* with respect to said substantially flat sheet-contacting facing surface and additionally including a ramp for supporting and guiding at least one of such photographic elements toward said canted platform as such sheet materials approach said pressure-generating gap, said ramp being canted at an acute angle with respect to said platform.
 11. The apparatus of claim 1 further including means for rapidly attaching and detaching said apparatus as a single unit from a camera.
 12. Apparatus for use in a camera of the self-developing type including an enclosed housing having an elongated exit port through which photographic film units, each of such film units comprising a first and a second sheet, may be withdrawn therefrom and means for mounting a plurality of such film units within such housing with said second sheets thereof disposed in a stacked array such that the leading edge of each such second sheet is spaced a given distance from the plane of such exit port and each such second sheet is disposed generally parallel to a plane perpendicular to such first-mentioned plane so that each is spaced a different distance from such second-mentioned plane, the improvement comprising: a pair of fluid spreader elements presenting elongated juxtaposed sheet-contacting facing surfaces defining a pressure-generating gap disposed to exert a compressive force on each pair of such first and second sheets as they progressively pass therebetween in superposed relationship towards said exit port to effect the spreading of a layer of processing fluid between each such pair of sheets, one of said facing surfaces being substantially flat and extending perpendicular to the plane of said gap; means for assuring that fluid layers of substantially the same thickness are spread between all such pairs of sheets as they are withdrawn from such camera, said means comprising a platform extending from a point adjacent one of said sheet-contacting facing surfaces towards such stacked array and away from said other sheet-contacting facing surface, and means for urging progressive sections of each such pair of sheets against each other as they are advanced from such stacked array toward said pressure-generating gap, one side of such stacked array of second sheets lying in a plane disposed on the other side of said substantially flat sheet-contacting facing surface from said other sheet-contacting facing surface and said platform extending from an end of said substantially flat sheet-contacting facing surface to a point intermediate said substantially flat sheet-contacting facing surface and such stacked array of second sheets; and means for supporting and guiding such second sheets as they approach said platform extending from the end of said platform furthermost removed from said substantially flat sheet-contacting facing surface to a point under such stacked array of second sheets.
 13. The apparatus of claim 12 wherein said platform is substantially flat and disposed at an angle on the order of 5 degrees with respect to said substantially flat sheet-contacting surface and said support and guiding means comprises a substantially flat ramp disposed at an angle on the order of 1* with respect to said platform.
 14. Photographic apparatus for spreading a processing fluid as a layer between two sheets of material responsive to relative motion being effected between said apparatus and such sheets, a first of such sheets comprising a relatively flexible photosensitive element having a latent image recorded thereon and the second of such sheets comprising a relatively stiff image-receiving sheet, said apparatus comprising: a first fluid spreader element formed of sheet material and including an elongated substantially flat sheet-contacting facing surface; a second fluid spreader element formed of sheet metal and including an elongated sheet-contacting facing surface having an arcuate cross-sectional configuration; and means for pivotally connecting said spreader elements together for selective movement between an operative position wherein said facing surfaces are disposed in juxtaposed relationship to exert a compressive force on such sheets as they progressively pass therebetween in superposed relationship to effect the spreading of a layer of such fluid between such sheets and an inoperative position wherein said facing surfaces are readily accessible for cleaning purposes, said flat sheet-contacting facing surface being disposed adjacent such second sheet during such fluid spreading operations and said arcuate sheet-contacting facing surface being disposed adjacent such first sheet during such fluid spreoading operations.
 15. Photographic apparatus for spreading a processing fluid as a layer between two sheets of material responsive to relative motion being effected between said apparatus and such sheets, comprising: a first fluid spreader element formed of sheet metal and including an elongated substantially flat sheet-contacting facing surface; a second fluid spreader element formed of sheet metal and including an elongated sheet-contacting facing surface having an arcuate cross-sectional configuration; and means for pivotally connecting said spreader elements together for selective movement between an operative position wherein said facing surfaces are disposed in juxtaposed relationship to exert a compressive force on such sheets as they progressively pass therebetween in superposed relationship to effect the spreading of a layer of such fluid between such sheets and an inoperative position wherein said facing surfaces are readily accessible for cleaning purposes.
 16. The apparatus of claim 15 wherein said connecting means comprises means for facilitating a given amount of displacement of at least one of said elements away from the other of said elements when said elements are disposed in their said operative positions and means for yieldably urging said elements towards one another at such times.
 17. Photographic apparatus for spreading a processing fluid as a layer between two photographic sheets responsive to relative motion being effected between said apparatus and such sheets, said apparatus comprising: a first fluid spreader element formed of sheet metal and including an elongated substantially flat sheet-contacting facing surface; a second fluid spreader element formed of sheet metal and including an elongated sheet-contacting facing surface having an arcuate cross-sectional configuration; means for mounting said fluid spreader elements with their said sheet-contacting facing surfaces disposed in juxtaposition to define a gap therebetween and for yieldably urging said fluid spreader elements toward each other; a substantially flat platform connected and extending from said substantially flat sheet-contacting facing surface in the direction that such photographic sheets are intended to approach said gap, said platform being disposed at an acute angle with respect to the plane of said gap and configured to provide a surface adapted to underlie sucH photographic sheets as they approach said gap; a ramp extending at an acute angle from said platform for supporting and guiding at least one of such photographic sheets toward said platform as such photographic sheets approach said gap; and means for urging spaced apart longitudinal edge portions of such photographic sheets toward each other but not into engagement with said platform.
 18. The apparatus of claim 17 wherein said platform is disposed at an angle of between 4* and 6* with respect to said substantially flat sheet-contacting facing surface and said ramp is disposed at an angle on the order of 1* with respect to said platform.
 19. Photographic apparatus for effecting the spreading of a processing fluid in a layer between a pair of sheet materials comprising: a pair of elongated juxtaposed sheet-contacting facing surfaces defining a pressure-generating gap to exert a compressive force on such sheets as they progressively pass therebetween in superposed relationship to effect the spreading of a layer of such fluid therebetween, one of said sheet-contacting facing surfaces being substantially flat and extending perpendicular to the plane of said gap; means for controlling the thickness of the layer of such fluid spread between such sheets as they pass between said sheet-contacting facing surfaces, said means comprising a substantially flat platform canted at an angle of between 4* and 6* with respect to said one facing surface as it approaches said pressure-generating gap, said platform extending from a point adjacent said one sheet-contacting facing surface away therefrom in the direction towards which such sheets are advanced towards such sheet-contacting facing surfaces, and means for urging progressive sections of such superposed sheets against each other as they are advanced towards said pressure-generating gap; and a ramp for supporting and guiding at least one of such sheet materials as such sheet materials approach said pressure-generating gap, said ramp being disposed at an angle on the order of 1* with respect to said platform. 